Breathing system protecting apparatus with a closed or semi-open circulation of respiration gas

ABSTRACT

A breathing apparatus with a closed or semi-open circulation of the respiration gas incorporating a discharge valve located in the exhalation conduit and an acoustic device for signaling dwindling supply of oxygen. The discharge valve is located between an exhalation check valve and a carbon dioxide absorber. The acoustic device comprises a signaling unit through which the respiration gas flows in a stream in parallel to the stream of gas flowing from a compressed oxygen reservoir to the utilization circuit for the user, the signaling unit being located inside an inflatable breathing bag, the body of the signaling unit being provided with side holes through which air is sucked, under injection effect, from the breathing bag.

United States Patent [191 Kowalski [451 Apr. 23, 1974 BREATHING SYSTEMPROTECTING APPARATUS WITH A CLOSED OR SEMI-OPEN CIRCULATION OFRESPIRATION GAS Alfred Kowalski, ul. Armii Czerwonej 6, Kalety, PolandFiled: Mar. 14, 1972 Appl. No.: 234,523

Inventor:

Foreign Application Priority Data April 17, 1971 Poland 147612References Cited UNITED STATES PATENTS 5/1964 Sajeck 128/142 fle FOREIGNPATENTS OR APPLICATIONS 10/1943 Switzerland 128/202 [57] ABSTRACT Abreathing apparatus with a closed or semi-open circulation of therespiration gas incorporating a discharge valve located in theexhalation conduit and an acoustic device for signaling dwindling supplyof oxygen. The discharge valve is located between an exhalation checkvalve and a carbon dioxide absorber. The acoustic device comprises asignaling unit through which the respiration gas flows in a stream inparallel to the stream of gas flowing from a compressed oxygen reservoirto the utilization circuit for the user, the signaling unit beinglocated inside an inflatable breathing bag, the body of the signalingunit being provided with side holes through which air is sucked, underinjection effect, from the breathing bag.

5 Claims, 1 Drawing Figure BREATHING SYSTEM PROTECTING APPARATUS WITH ACLOSED OR SEMI-OPEN CIRCULATION OF RESPIRATION GAS BACKGROUND a. Fieldof the Invention The present invention relates to a respirator orbreathing apparatus having a closed or partly open circulation of therespiration gas.

b. Prior Art In most modern constructions of respirators or breathingapparatus a discharge valve is situated in the exhalation conduit of theapparatus. The discharge valve serves to expel exhaled gas whichcontains high concentration of CO in order to extend the life of a Cabsorber located downstream thereof. Such an arrangement of thedischarge valve also insures that there is less CO contained in theinhaled air. An efficient discharge system is formed by two dischargevalves arranged in series, one valve being a check valve of pressuretype and the other a cut-off, trigger valve actuated by the pressureexerted by the wall of a fully inflated breathing bag. The trigger valveserves as a pressure type, discharge valve proper, while the check valveprevents any toxic gas from penetrating into the apparatus from thesurrounding atmosphere. Such penetration of a toxic gas might take placein the first phase of inhalation when a still partially inflatedbreathing bag holds the trigger valve in its open position, and whenthere is an inhalation vacuum present in the space where the dischargevalve is installed. In the existing apparatus whose construction is mostapproximate to that of the invention the discharge valve is situated inthe exhalation conduit before the exhalation check valve.

The shortcoming of such a construction is that the exhaled air isdischarged only during a very short end phase of exhalation. In thefirst phase of exhalation the trigger valve is closed, in spite of thepressure present in the exhalation conduit and in spite of the dischargecheck valve being open, because the breathing bag is not yet fullyinflated. The trigger valve opens in the end phase of exhalation but theflow through this valve quickly stops, since as soon as inhalationbegins, the inhalation vacuum holds the discharge check valve in itsclosed position. This opposed operation of the valves has an impairingeffect on the benefits resulting from favorable location of thedischarge valve.

Another constructional deficiency which impairs the time period in whichthe apparatus can be used, is the location of a signal device forsignaling dwindling supply of the respiration gas. These devices used inapparatus with a closed or a semi-open gas circulation are usuallyconstituted as whistles or buzzers which are actuated by being connectedin series in the respiration air circuit at the moment when the pressurein the reservoir drops below a certain value. The actuation of thesedevices in the respiration gas circuit produces an increase in theresistance to breathing thus requiring an increased effort by the lungsof an already tired user of the apparatus which in turn leads to a rapidexhaustion of the gas supply.

SUMMARY OF THE INVENTION An object of the present invention is toprovide a respirator of such construction as to extend the operationperiod of the apparatus or if the present operation time is maintained,to reduce the weight of the apparatus.

In order to attain this objective, a modification is made in thelocation of the discharge valve and of the oxygen supply signalingdevice so as to provide a system which is free of the above describeddeficiencies of the known apparatus.

According to the invention, the discharge valve is located in theexhalation conduit between the exhalation check valve and the COabsorber, while an acoustic alarm unit for signaling a dwindling supplyof oxygen is located inside the breathing bag, the stream of gas flowingthrough the signaling device being in parallel to the ordinary stream ofrespiration gas which flows in the circuit from the gas supply to theuser.

BRIEF DESCRIPTION OF THE DRAWING The sole FIGURE of the drawingdiagrammatically illustrates the apparatus in an exemplary constructionaccording to the invention.

DETAILED DESCRIPTION The apparatus comprises a reservoir or tank 1 ofcompressed oxygen connected, through a system of valves, with aninflatable exhalation bag 2, said bag in turn forming a closed circuitwith a carbon dioxide absorber 3 by means of breathing hoses 4, 6 andconduits 7 and 8 at the inlet and the outlet of the CO absorber. Onlycertain valves in the valve system of the apparatus are essential forexplaining the substance of the present invention and will be describedhereafter.

Located at the outlet of the reservoir 1 is a cut-off valve 9, connectedwith a pressure reducing valve 10. A high-pressure chamber 11 of thepressure reducing valve 10 is connected with a chamber 23 of an oxygensupply signaling device 22, while a reduced pressure chamber 32 of valve10 is connected with a feed valve 12 connected by means of a conduit 13with inhalation hose 4. Installed between the inhalation hose 4 andexhalation hose 6 is mouthpiece 5. The hoses are terminated with aninhalation check valve 14 and an exhalation check valve 15.

Mounted on inlet conduit 7 of theabsorber 3 is a discharge valve 16comprising a check valve 17 and a trig ger valve 18. Valve 18 isprovided with a spring 19 and a movable element 20. Connected to element20 is an actuator 21 having a function to be described later.

The device 22 for signaling low supply of oxygen is provided with acontrol element 24 urged under the pressure in chamber 22 against amovable element 26 ofa valve 25. A spring 27 acts on element 26 in adirection to open valve 25. A signaling unit 28 in the signaling device22 comprises a nozzle 29, a whistle 31, and

holes 30 in the side wall of the signaling device.

When the valve 9 of reservoir 1 is open, the oxygen flows to thepressure reducing valve 10 wherefrom, under reduced pressure, the oxygenflows to the feed valve 12. Valve 12 ensures a constant and periodicallyincreased feeding, through conduit 13, to the inhalation hose 4. In theinhalation hose 4 the oxygen joins the air circulating in the circuitand flows, during the inhalation phase to the mouthpiece 5 and to thelungs of the user of the apparatus. During exhalation, the air flowsthrough the exhalation check valve 15 through the absorber 3, to the bag2 causing inflation of the bag, and then the breathing cycle isrepeated. During exhalation, the check valve 17 of the discharge valve16 is opened by the pressure prevailing in the conduit 7. In the finalphase of exhalation, the inflated bag presses against the releaseactuator 21 of the valve 18 and the valve 18 opens thus enabling a partof the exhaled air to be discharged to the outside atmosphere. As soonas exhalation ends, and the pressure in the breathing conduits 4 and 6diminishes, the exhalation valve closes. Nevertheless, the flowresistance of the absorber 3 causes pressure to remain in the conduit 7.Therefore, the air from the final phase of exhalation in conduit 7 willbe discharged through the open check valve 17 and the trigger valve 18,even during the initial inhalation phase until the wall of the bag 2ceases pressing against the release actuator 21. This protractedoperation of the discharge valve causes the absorber to purify air whoseCO content is small and consequently the life of the absorber isextended, or alternatively the size and the weight of the absorber canbe reduced for the same life. In both instances, absorption of the CO inthe absorber is almost complete. The above described system ofdischarging the air from the circuit can be employed for every apparatusof a closed or semi-open circulation type. The apparatus operates in theabove fashion until the moment when the acoustic device signals adwindling supply of oxygen. This device begins operation when thepressure in the compressed oxygen reservoir 1, and thus in the reservoirspace 23 of the signaling device, drops below a predetermined value. Assoon as this occurs, the force of spring 27 overcomes the pressureexerted by the controlling element 24 on the movable element 26 of thevalve 25 and opens the valve 25. The oxygen in the space between thepressure reducing valve 10 and the feed valve 12 flows through the valve25 and the nozzle 29, to the whistle 31. The stream of oxygen comingfrom the nozzle 29 and directed towards the whistle sucks air, underinjection effect, from the breathing bag through the side holes 30 inthe wall of the signaling unit 28, and thus a greater part of the gasflowing through the whistle 31 produces a stronger whistling effect.

There is not any increased resistance to the breathing effort when theacoustic device is operative. Nor is there a greater gas consumptionfrom the gas cylinder since an automatic reduction to a minimum of thegas flow takes place by means of the feed valve 12. A further noteworthyproperty of the signaling device is that this device stops producingsignals as soon as the flow of respiration gas from the reservoir to thebag is completely terminated, this being a signal for immediate stoppageof the apparatus. The period of time for working with the apparatus hassafely been brought up to a peak value without the need of maintaining acertain reserve in the respiration gas supply.

What is claimed is:

1. In a respirator having a supply of respiration gas, an inhalationconduit connected to the supply for utilization by a user of therespirator, an exhalation conduit for receiving exhaled gases from theuser,an absorber of CO gas connected to the exhalation conduit, and aresilient bag connected to the absorber and undergoing inflation duringexhalation and deflation during inhalation, an improvement comprisingdischarge valve means in the exhalation conduit for discharging exhaledgases to ambient atmosphere during at least part of the exhalationperiod by the user, a check valve in said exhalation conduit, saiddischarge valve means being located in the exhalation conduit betweenthe check valve and the absorber, conduit means connecting the gassupply to the inhalation conduit, signal means for indicating dwindlingsupply of the supply gas, said signal means being connected in parallelwith the conduit means, said signal means comprising an acoustic signalgenerator disposed in said resilient bag.

2. The combination as claimed in claim 1 wherein said acoustic signalgenerator is provided with holes which open into the interior of theresilient bag to induce flow of the gas therein through the signalgenerator to produce an acoustic signal.

3. The combination as claimed in claim 2 wherein said signal generatorincludes a nozzle through which supply gas can be passed to produce anaudible sound when the pressure of the supply gas drops below a givenvalue, said holes in the signal generator leading to the path of flow ofthe gas to the nozzle and to the interior of said resilient bag so thatthe gas in the resilient bag is drawn to the nozzle by injection effectwhen supply gas flows to the nozzle.

4. The combination as claimed in claim 3 wherein said signal meanscomprises a valve which is normally closed by the pressure of the supplygas but which is opened due to low pressure when the gas supply hasdwindled below a predetermined amount, the latter valve being disposedin front of the signal generator to control flow of supply gas to saidnozzle.

5. The combination as claimed in claim 1 wherein said discharge valvemeans includes an actuator member positioned proximate the resilient bagto be actuated thereby when the bag undergoes inflation.

1. In a respirator having a supply of respiration gas, an inhalationconduit connected to the supply for utilization by a user of therespirator, an exhalation conduit for receiving exhaled gases from theuser, an absorber of CO2 gas connected to the exhalation conduit, and aresilient bag connected to the absorber and undergoing inflation duringexhalation and deflation during inhalation, an improvement comprisingdischarge valve means in the exhalation conduit for discharging exhaledgases to ambient atmosphere during at least part of the exhalationperiod by the user, a check valve in said exhalation conduit, saiddischarge valve means being located in the exhalation conduit betweenthe check valve and the absorber, conduit means connecting the gassupply to the inhalation conduit, signal means for indicating dwindlingsupply of the supply gas, said signal means being connected in parallelwith the conduit means, said signal means comprising an acoustic signalgenerator disposed in said resilient bag.
 2. The combination as claimedin claim 1 wherein said acoustic signal generator is provided with holeswhich open into the interior of the resilient bag to induce flow of thegas therein through the signal generator to produce an acoustic signal.3. The combination as claimed in claim 2 wherein said signal genEratorincludes a nozzle through which supply gas can be passed to produce anaudible sound when the pressure of the supply gas drops below a givenvalue, said holes in the signal generator leading to the path of flow ofthe gas to the nozzle and to the interior of said resilient bag so thatthe gas in the resilient bag is drawn to the nozzle by injection effectwhen supply gas flows to the nozzle.
 4. The combination as claimed inclaim 3 wherein said signal means comprises a valve which is normallyclosed by the pressure of the supply gas but which is opened due to lowpressure when the gas supply has dwindled below a predetermined amount,the latter valve being disposed in front of the signal generator tocontrol flow of supply gas to said nozzle.
 5. The combination as claimedin claim 1 wherein said discharge valve means includes an actuatormember positioned proximate the resilient bag to be actuated therebywhen the bag undergoes inflation.